1. Field of the Invention
The invention relates to an addition-crosslinkable silicone mixture (S) comprising, as an additive, 3-amino-1,2,4-triazole-5-thiol bonded to silica.
2. Description of the Related Art
EP 0 834 534 A1 describes compositions which comprise organic sulfur compounds as additives for lowering compression set, these compositions being crosslinkable to give elastomers. The organic sulfur compounds can have been applied to an inorganic filler.
EP 0 442 143 A1 describes a process for the production of oxidic or silicatic fillers surface-modified with 3-thio-cyanatopropyltriethoxysilane or bis(3-trimethoxysilylpropyl)tetrasulfane.
The best reduction of compression set is achieved by 3-mercapto-1,2,4-triazole. U.S. Pat. No. 5,104,919 describes silicone compositions curable via addition crosslinking which comprise triazole compounds, among which is 3-mercapto-1,2,4-triazole.
To improve the dispersion thereof, the triazole compound is added to the composition in the form of a solution in an organic solvent. The rubber thus becomes slightly yellow and cloudy.